The television (TV) has gradually become essential household entertainment equipment due to its distinct advantages since it was developed. However, such phenomenon often occurs in real life, in which a sound with a large volume is output suddenly when the TV is turned on and other people may be disturbed. When the viewer is watching TV, he or she cannot hear the sound of the TV clearly since the surrounding noise is too loud. Alternatively, when multiple people are chatting and no one is watching TV, the sound of the TV may affect the chat. At this time, the viewer needs to search a remote controller everywhere or to come up to the TV to adjust the volume.